1. Field of the Invention
The present invention relates to a condenser, a coolant system, and an on vehicle air conditioning system.
2. Background Art
As is commonly known, an on vehicle air conditioning system includes a blower fan, an air conditioning unit provided with a heater core for heating type air conditioning, and various types of dampers, a heat source system for introducing high temperature cooling water into the air conditioning system, a coolant system for supplying coolant to an evaporator in the air conditioning unit, and a controller for controlling operations of the on vehicle air conditioning system in response to various conditions determined by the driver's choice such as the temperature.
The coolant system usually includes a compressor for feeding a coolant gas and, in order to lubricate the compressor, it is usual to circulate oil corresponding to several percent of the flow rate of the coolant in the coolant system.
A conventional example of the coolant system is described with reference to FIG. 7. In FIG. 7, the reference numeral 100 denotes a compressor. The compressor 100 has the function of compressing the low temperature and low pressure coolant gas which has been evaporated in an evaporator 101 by absorbing heat in a compartment of the vehicle, and forwarding the coolant as high temperature and high pressure gas coolant.
In the condenser 102, the high temperature and high pressure gas coolant supplied from the compressor 100 is condensed into liquid through condensation and liquefaction by cooling the gaseous coolant by outside air. The thus liquefied coolant is sent to the receiver 103 to be subjected to gas liquid separation and then supplied to an expansion valve (not shown) as high temperature and high pressure coolant. In this expansion valve, the high temperature and high pressure coolant is subjected to pressure reduction and expansion, so that the coolant is converted into the low temperature and low pressure liquid (atomized) coolant and supplied to the evaporator 101. In addition, an oil separator 104 is provided at the discharge side of the compressor 100.
The oil separator 104 is provided in the compressor at the discharge side, where the oil is necessary. The coolant system is constituted such that the oil separated and collected at the discharge side of the compressor is again supplied to the intake side of the compressor.
Since provision of the oil separator allows recovery of the oil before the condenser 102, an advantageous feature of the conventional on vehicle air conditioning system is obtained in that it is possible to prevent reduction of the heat efficiency due to adhesion of oil on the heat exchanging surfaces of the condenser 102 and to prevent an increase of the boiling temperature of the coolant by incorporation of oil in the coolant. However, a problem is encountered that there may be no space to provide even a small part in the engine compartment of a vehicle, since it is fully occupied by various accessories, which causes the problem that the addition of the oil separator to the engine compartment may not be possible.
As measure to respond to the above problem, it has been considered to integrate the oil separator 104 with the compressor 100. However, since the oil separator 104 requires a certain space for gas-liquid separation, it is not possible to reduce the volume of the oil separator 104 by merely integrating with the compressor, and the problem of space remains.